Recently, a high-density optical record medium such as BD-RE (rewritable Blu-ray disc) enabling to record and store massive high-definition video data and high-quality audio data is expected to be developed and marketed.
The BD-RE, as shown in FIG. 1, is divided into a lead-in area, a data area, and a lead-out area. And, an inner spare area (ISA) and an outer spare area (OSA) are allocated to a front head and a rear end of the data area, respectively.
In the BD-RE, data is recorded by cluster unit as a predetermined record unit. Owing to the features of a rewritable disc, data can be repeatedly written in a specific area of the disc, which is called ‘physical overwrite’. In the course of writing data, it is detected whether a defective area or cluster, as shown in FIG. 1, exists within the data area.
If the defective area is detected, a replacement write operation of recording the data written in the defective area in a spare area, e.g., inner spare area (ISA), is performed as well as management information including location information of the defective area and location information of the replaced data in the spare area is recorded in a defect list in a defect management area (DMA) within the lead-in area.
Meanwhile, standardization for BD-WO (Blu-ray disc write-once) is being discussed. As data can be written in an entire area of a write-once optical disc once only, the physical overwrite is impossible for the write-once optical disc.
However, in order to edit recorded data in the write-once optical disc, to amend a corresponding portion of the recorded data, or to provide user's or host's convenience, the overwrite may be needed. Hence, an effective system enabling the overwrite for the write-once optical disc is urgently needed.